Article-lifting attachment for an excavator

ABSTRACT

An attachment for a backhoe to enable the digging bucket thereof to pickup and lift articles such as boulders and logs which are too large to fit inside of the bucket. The attachment includes a chain fastened to the rear of the bucket, extending forwardly across the open side of the bucket and anchored to a pipe which is pivoted on and urged away from the dipper stick of the backhoe. The chain automatically wraps around the article and cinches the article onto the bucket as the latter is swung forwardly into lifting engagement with the article.

United States Patent Harry C. Clark 226 W. Perry St., Belvidere, II]. 61008 37,535

May 15, 1970 Oct. 19, 1971 Inventor Appl. No. Filed Patented ARTlCLE-LIFTING ATTACHMENT FOR AN EXCAVATOR 138 B, I38 C,l44, 145,147 R, 147 G, 654; 294/86.28, 99, 86

Primary ExaminerGerald M. Forlenza Assistant Examiner-Jerold M. Forsberg Attorney-Wolfe, Hubbard, Leydig, Voit & Osann ABSTRACT: An attachment for a backhoe to enable the digging bucket thereof to pickup and lift articles such as boulders and logs which are too large to fit inside of the bucket. The attachment includes a chain fastened to the rear of the bucket, extending forwardly across the open side of the bucket and anchored to a pipe which is pivoted on and urged away from the dipper stick of the backhoe. The chain automatically wraps around the article and cinches the article onto the bucket as the latter is swung forwardly into lifting engagement with the article.

ARTICLE-LIFTING ATTACHMENT FOR AN EXCAVATOR BACKGROUND OF THE INVENTION This invention relates to an article-lifting attachment for an excavator of the type having a generally upright swingable boom and a digging bucket pivoted to swing back and forth on the lower end of the boom. More particularly, the invention relates to an attachment which coacts with the bucket to enable the bucket to pick up and carry large articles such as boulders, logs and the like which are too big to fit inside of the bucket.

' SUMMARY OF THE INVENTION The primary aim of the present invention is to provide a new and easily installed article-lifting attachment of the above character which, as compared to prior attachments used for .the same general purpose, is simpler and less expensive in construction and which, at the same time, operates automatically in conjunction with the normal back and forth swinging of the bucket to enable the picking up and lifting of articles by the bucket without need of separately controlling or actuating the "lifting attachment.

A more detailed object is to provide a lifting attachment having a flexible element such as a chain which first holds an article against any substantial movement to enable the bucket to be swung under the article and then automatically wraps around the article to cinch the latter securely onto the bucket.

These and other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings.

2 BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT For purposes of illustration, the invention is shown in the drawings in conjunction with an excavator of the so-called backhoe type in which an articulated boom 11 is pivoted at 13 on the rear end of a tractor l4 and carries a digging bucket 15 that is pivoted on the lower free end of the boom. The general construction and operation of such excavators are well known and thus will be described only briefly herein.

The boom 11 is formed by an elongated main arm or mast l6 fulcrumed at one end on the pivot 13 for vertical swinging and having a horizontal pivot 17 at its free end supporting the second am 19 of the boom, the latter arm commonly being called a dipper stick. The bucket IS, in turn, is pivoted on the lower end of the dipper stick to turn about a generally horizontal axis.

With the foregoing arrangement, vertical movement of the bucket 15 is accomplished with the usual operating mechanism including hydraulic cylinders 20 and 21. The cylinder 20 acts between a platform 23 on the rear of the tractor l4 and a pivot 24 on the upper end of the dipper stick 19 to swing the latter back and forth. The cylinder 21 is fastened at one end to the upper portion of the dipper stick and at the other end to ears 25 (FIG. 4) on the bucket to rock the bucket about its pivot. An additional cylinder (not shown) acts between the platform 23 and the mast 16 to swing the latter upwardly and downwardly and, to swing the boom 11 from side-to-side, the operating mechanism also includes a power actuator (not shown) for rotating the platform about a vertical axis.

The usual bucket 15 is fonned by two sidewalls 30 (FIG. 4) disposed in vertical planes, a generally rectangular rear side 31 on which the ears 25 are supported, and a curved bottom plate 33 terminating at the front side of the bucket in a digging edge that is usually provided with spaced, forwardly extending teeth 34. The top of the bucket is open and is spanned along its rear by a rectangular bar 35 supporting upstanding ears 36 through which a pivot pin 37 extends to connect the bucket to the dipper stick 19.

Prior to excavating, it is usually necessary to clear thearea of all large objects andarticles which would interfere with the digging operation. Previously, various devices have been attached to the excavator 10 to enable articles which are too large to fit into the bucket 15 to be picked up by the bucket and carried to other areas.

The present invention contemplates providing the excavator 10 with a new and improved article-lifting attachment which is simpler and less expensive in construction than those previously used and which, in addition, may be attached to and detached from the excavator more quickly and easily than has been possible heretofore. Moreover, the present lifting attachment coacts automatically with the bucket 15 to pick up articles in response to the normal swinging motions of the bucket and thereby eliminates the need of providing an additional operating mechanism for controlling the attachment.

In the present instance, the lifting attachment comprises a flexible element in the form of a chain 40 which is located adjacent the bucket 15 and serves first to restrain an article such as a log 41 against any substantial forward movement as the bucket is initially swung into lifting engagement with the log. With continued upward swinging of the bucket to raise the log, the chain automatically wraps around the log and cinches the log tightly onto the bucket to prevent the log from falling off of the bucket during transfer of the log to a different area.

As shown most clearly in FIG. 4, the chain 40 is arranged as a V which overlies the top of the bucket 15 and includes two rearwardly diverging and laterally spaced integral sections 43 anchored to the bucket. While such anchoring can be accomplished in many different ways, the rear end portions of the chain sections herein are simply looped around the rectangular bar 35 and fastened back upon themselves by hooks 44 (FIG. 5) carried on the ends of the sections. At the front of the V, the chain is looped around and welded at 45 (FIG. 4) to the lower end portion of an elongated armlike member 46 which simply may be a piece of iron pipe. The latter is pivoted at its upper end to the forward side of the dipper stick 19 as indicated at 47 and is urged outwardly away from the boom by a coil spring50 which is compressed between the dipper stick and the pipe 46. The pivot 47 may comprise a bolt extending through a hole in the pipe and through ears on the dipper stick while the spring 50 may be welded to the pipe and fastened detachably to the dipper stick by a removable plate (not shown) or in any other suitable manner.

The pipe 46 is centered with respect to the bucket 15 and the dipper stick l9 and extends forwardly of the bucket and downwardly to the approximate level of the digging teeth 34 when the bucket is positioned as shown in FIG. I. To lift and move a large article such as the log 41, the excavator 10 first is maneuvered by suitably controlling the dipper stick and the bucket until the chain 40 is positioned directly over the log and the bucket just' behind the log (see FIG. 1). In this position, the pipe 46 is extended forwardly by the spring 50 and thus the chain 40 is held taut between the pipe and the bar 35, the chain limiting the extent of forward swinging of the pipe.

With the bucket 15 and the chain 40 thus positioned, the bucket is moved into lifting engagement with the log 41 (see FIG. 2) by swinging the bucket forwardly about the pin 37 and, if necessary, by swinging the dipper stick forwardly about the pivot 17 During initial forward swinging of the bucket, the taut chain 40 engages the top of the log and prevents the latter from rolling forwardly as the teeth 34 and the forward edge of the bucket move beneath and lift the log. As the forward and upward swinging of the bucket is continued, the log forces the chain to flex upwardly (see FIG. 2) such that the chain begins to wrap around the log and pulls the pipe 46 rearwardly toward the bucket. Thereafter, the log is pulled rearwardly onto the upper edges of the sideplates 30 (see FIG. 3) of the bucket with the chain cinched tightly around the log and with the pipe 46 pulled into engagement with the teeth 34 to prevent the log from rolling ofi of the bucket. The excavator then may be moved to transfer the log to a different location.

From the foregoing it will be apparent that the present invention brings to the art a new and improved lifting attachment of comparatively simple and low-cost construction which may be installed on the excavator 10 by simply attaching the pipe 46 to the dipper stick 19 and hooking the chain 40 around the bar 35. The spring 50 automatically keeps the pipe 46 in an extended position and the chain 40 taut prior to lifting an article and enables the chain to be positioned easily over the article simply by maneuvering the bucket and the dipper stick. In addition, the chain automatically wraps around the article as the bucket is swung forwardly and thus actuators other than those already installed on the excavator are not required.

I claim as my invention:

1. An article-lifting device for use with an excavator having a generally upright swingable boom and a digging bucket pivoted to swing back and forth on the lower end of the boom, said device comprising a member pivoted intermediate the ends of the boom and extending outwardly from the boom and downwardly toward the bucket, an elongated flexible element extending from the lower end portion of said member toward the boom and extending over the open side of the bucket, and means normally urging said member away from the boom to keep said flexible element taut and yielding to allow swinging of the member toward the boom as an article is grabbed between said flexible element and said bucket and as the flexible element wraps around the article.

2. An article-lifting device as defined in claim 1 in which said means comprises a coil spring compressed between said member and said boom.

3. An article-lifting device as defined in claim 1 in which said flexible element comprises a chain.

4. An article-lifting device as defined in claim 3 in which said chain is fastened to the lower end portion of said member and is fastened adjacent the pivot connection between said bucket and said boom.

5. An article-lifting device as defined in claim 1 in which said member comprises an elongated arm pivoted on said boom and substantially centered with respect to said bucket, said flexible element comprising chain means fastened to the lower end portion of said arm and having sections diverging away from one another as they extend toward said boom whereby the chain means defines a V overlying the open side of the bucket.

6. An article-lifting device as defined in claim 5 in which the ends of said chain sections are fastened to said bucket adjacent the pivot axis thereof.

7. An article-lifting device for use with a backhoe having a generally upright swingable dipper stick and a digging bucket pivoted to swing back and forth on the lower end of the dipper stick, said device comprising an arm pivoted intermediate the ends of the dipper stick and extending downwardly and forwardly thereof, the lower end of said arm being located approximately at the same level as the digging edge of said bucket and normally being spaced forwardly of the digging edge, a chain extending rearwardly from the lower end of said arm over the open side of said bucket and anchored adjacent the rear side of the bucket, and a spring between said dipper stick and said arm normally urging said arm away from said dipper stick to keep said chain taut and yielding to allow swingintg of the arm toward the dip er stick as an article is grab e between said chain and sat bucket and as the chain wraps around the article upon forward swinging of the bucket. 

1. An article-lifting device for use with an excavator having a generally upright swingable boom and a digging bucket pivoted to swing back and forth on the lower end of the boom, said device comprising a member pivoted intermediate the ends of the boom and extending outwardly from the boom and downwardly toward the bucket, an elongated flexible element extending from the lower end portion of said member toward the boom and extending over the open side of the bucket, and means normally urging said member away from the boom to keep said flexible element taut and yielding to allow swinging of the member toward the boom as an article is grabbed between said flexible element and said bucket and as the flexible element wraps around the article.
 2. An article-lifting device as defined in claim 1 in which said means comprises a coil spring compressed between said member and said boom.
 3. An article-lifting device as defined in claim 1 in which said flexible element comprises a chain.
 4. An article-lifting device as defined in claim 3 in which said chain is fastened to the lower end portion of said member and is fastened adjacent the pivot connection between said bucket and said boom.
 5. An article-lifting device as defined in claim 1 in which said member comprises an elongated arm pivoted on said boom and substantially centered with respect to said bucket, said flexible element comprising chain means fastened to the lower end portion of said arm and having sections diverging away from one another as They extend toward said boom whereby the chain means defines a V overlying the open side of the bucket.
 6. An article-lifting device as defined in claim 5 in which the ends of said chain sections are fastened to said bucket adjacent the pivot axis thereof.
 7. An article-lifting device for use with a backhoe having a generally upright swingable dipper stick and a digging bucket pivoted to swing back and forth on the lower end of the dipper stick, said device comprising an arm pivoted intermediate the ends of the dipper stick and extending downwardly and forwardly thereof, the lower end of said arm being located approximately at the same level as the digging edge of said bucket and normally being spaced forwardly of the digging edge, a chain extending rearwardly from the lower end of said arm over the open side of said bucket and anchored adjacent the rear side of the bucket, and a spring between said dipper stick and said arm normally urging said arm away from said dipper stick to keep said chain taut and yielding to allow swinging of the arm toward the dipper stick as an article is grabbed between said chain and said bucket and as the chain wraps around the article upon forward swinging of the bucket. 